Memory Consumption by Object
SQL Server caches object data in memory in the buffer pool. Understanding memory consumption by object can be crucial for performance. For instance, you may have a large logging table consuming 90% of the buffer…
dm_db_database_page_allocations
sys.dm_db_database_page_allocations is an undocumented SQL Server T-SQL Dynamic Management Function. This DMF provides details about allocated pages, allocation units, and allocation extents. The function definition in SQL Server 2016 is:
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create function sys.dm_db_database_page_allocations ( @DatabaseId SMALLINT, @TableId INT = NULL, @IndexId INT = NULL, @PartitionId BIGINT = NULL, @Mode NVARCHAR(64) = 'LIMITED' ) returns table as return select DA.[database_id], DA.[object_id], DA.[index_id], DA.[partition_id], DA.[rowset_id], DA.[allocation_unit_id], DA.[allocation_unit_type], IP.[name] as 'allocation_unit_type_desc', DA.[data_clone_id], DA.[data_clone_state] as 'clone_state', case (DA.[data_clone_state]) when 0 then N'PRIMARY' else N'SECONDARY' end AS clone_state_desc, DA.[extent_file_id], DA.[extent_page_id], DA.[allocated_page_iam_file_id], DA.allocated_page_iam_page_id, DA.[allocated_page_file_id], DA.allocated_page_page_id, DA.is_allocated, DA.is_iam_page, DA.is_mixed_page_allocation, DA.page_free_space_percent, DA.page_type, DA.page_type_desc, DA.page_level, DA.next_page_file_id, DA.next_page_page_id, DA.previous_page_file_id, DA.previous_page_page_id, DA.is_page_compressed, DA.has_ghost_records from openrowset (table DM_DB_DATABASE_ALLOCATIONS, @DatabaseId, @TableId, @IndexId, @PartitionId, @Mode) DA JOIN sys.syspalvalues IP ON IP.[class] = 'AUTY' AND IP.[value] = DA.[allocation_unit_type] |
The function definition tells…
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